The general objectives of this proposal are 1. to biochemically characterize the types of protein kinase and phosphoproteins in human prostatic fluid and 2. to identify and age- or disease-related changes in these enzymes and phosphoproteins. Preliminary experiments indicate that the pattern of phosvitin and histone protein kinase activities in prostatic fluid change with prostate cancer. Therefore, other types of protein kinase (e.g., Ca++ dependent, tyrosine-specific, etc.) which may be in prostatic fluid may be susceptible to change. The presence of other types of protein kinase will be examined and characterized by use of specific substrates. activators, and inhibitors. Since cancer of the prostate appears to reflect specific alterations in the pattern of activities of different types of protein kinase, the activities of individual isoenzyme forms of these kinases may be responsible for these overall changes. If specific isoenzymes are responsive to change due to cancer, isoenzyme measurements would make the use of protein kinase activities more sensitive to detect the pathological change. The study of protein kinase isoenzymes will utilize electrophoretic separation methods in combination with the assay of individual types of protein kinase activities right in the electrophoretic gel. Other separation techniques will be explored to determine whether a simple preliminary step(s) befire electrophoresis and kinase assay might increase the sensitivity of measurement of some forms of protein kinase. Some examples are: separation of soluble and membrane fractions by ultracentrifugation, affinity chromatography, ion-exchange chromatography, etc. Prostatic fluid samples from men with chronic prostatitis, benign prostatic hyperplasia, prostatic cancer, or no known prostate disease will be studied. Comparisons of the findings among these groups will establish the relationship of various changes in protein kinase activities to particular prostatic diseases, and determine the specificity of such changes to prostatic cancer. In addition, since protein phosphorylation is an improtant mechanism for regulating biological functions, these basic studies should provide important information on protein kinases themselves, and prostatic secretory function, the prostatic acinar cell milieu, and male reproductive function.